Electric welding ground pad



Aug. 7, 1962 J. A. ROBINSON 3,

ELECTRIC WELDING GROUND PAD Filed Oct. 28, 1959 John A. Rob/715m 1N VEN TOR.

United States Patent Ofiice Edlififlil? Patented Aug. 7, 1962 3,048,807 ELECTRIC WELDING GROUND PAD John A. Robinson, Warm Springs, Mont. (1011 Wilder Ave., Helena, Mont.) Filed Oct. 28, 1959, Ser. No. 849,373 3 Claims. (Cl. 339-12) This invention relates to electrical grounds and more particularly to a ground pad adapted to be used with electric welders.

An object of the invention is to provide an easily used, safe and positive ground connection which is principally useful in connection with electric welders.

A feature of the invention is found in the manner of connection with a ground conductor, for example, the work. A permanent magnet is used for this purpose whereby it is very simple to establish a ground, thereby obviating the necessity of hooks, clamps and pliers and all other ground clamps and pads which have a tendency to fall, become loose or become useless after a period of time. The magnet in the ground pad of the invention stays in place when it is attached to the workpiece, simply by placing it thereon. No movement will ordinarily remove or knock off the magnet thereby avoiding the usual difiiculty, i.e. breaking the arc.

Another feature of importance of the invention is that it saves the time of the welder since there is no searching for a place to attach a clamp onto the workpiece. The magnet will adhere to essentially any part of the workpiece by simply laying it in place.

Briefly, the invention is embodied in a permanent magnet together with a connecting device holding the magnet fastened to the end of the conductor which is ordinarily part of the electric welding assembly.

These together with other objects and advantages which will become subsequently apparent reside in the details of construction and operation as more fully hereinafter described and claimed, reference being had to the accompanying drawings forming a part hereof, wherein like numerals refer to like parts throughout, and in which:

FIGURE 1 is a perspective view of an electric welding ground pad in accordance with the invention.

FIGURE 2 is a longitudinal sectional view of the pad of FIGURE 1.

FIGURE 3 is a transverse sectional view taken on the line 3-3 of FIGURE 2.

FIGURE 4 is a transverse sectional view taken on the line 4-4 of FIGURE 2.

FIGURE 5 is a transverse sectional view taken on the line 5-5 of FIGURE 2.

In the accompanying drawings there is illustrated an electric welding ground pad which diagrammatically represents the principles of the invention. A conventional conductor 12 having an insulation covering 14 thereon is mechanically connected with a conductive tube 16. The tube has a cylindrical end 18 providing a handle and a partially cylindrical end 20 integral therewith. The conductor is skinned back leaving a copious quantity of the conductive wires which rest on the bottom surface of the partially cylindrical part 20 of the tube 16.

Part 20 of tube 16 is made with an essentially channelshaped section, for instance by splitting a perfectly cylindrical tube and opening the sides thereof to form an upwardly opening trough or pocket 22. Clamp 24 is located in pocket 22 and is composed of sleeve 26 having pairs 28 and 34 of openings therein accommodating two bolts 32 and 34 respectively. The bolts have nuts 36 thereon and they extend through apertures 38 in the bottom part of the pocket. The strands of the conductor are interposed between the bottom part of the pocket 22 and the lower surface of sleeve 24 and are firmly held in place by tightening nuts 36.

lermanent magnet 40, for example, a horseshoe magnet, is secured to the lower part or wall of pocket 22 at the outer end of tube 16. Aperture 42 is in the center of the magnet 40 and has a mounting bolt 44 extended therethrough. This mounting bolt also extends through an aperture 46 in the bottom part of pocket 22 thereby firmly securing the magnet in place on tube 16.

This completes the construction of pad 10. Its use has been previously discussed. To review, the magnet 40 is simply placed on the work thereby automatically establishing a certain, secure and lasting ground connection for an electric welder.

The foregoing is considered as illustrative only of the principles of the invention. Further, since numerous modifications and changes will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction and operation shown and described, and accordingly all suitable modifications and equivalents may be resorted to, falling within the scope of the invention as claimed.

What is claimed as new is as follows:

1. A portable electric welding ground pad comprising, in combination, a cylindrical metallic tube for longitudinally receiving an insulated electric conductor, a metallic trough of generally U-shaped cross section integral with one end of said tube in longitudinal alignment and communicating therewith for longitudinally receiving a bare end portion of the conductor therefrom, means securing said bare conductor end portion in the trough, a permanent horseshoe magnet, and means securing said magnet beneath the free end portion of the trough, said trough having a series of longitudinally spaced openings in its bottom, the first-named means including a cylindrical tubular clamp of uniform diameter from end to end removably mounted longitudinally in the trough within the confines thereof and resting on the bare conductor end portion, said clamp having diametrically opposite openings therein at longitudinally spaced points aligned with the innermost of the first-named openings, and nutted bolts in the aligned openings passing through the bare conductor end portion for tightening the clamp thereon.

2. A portable electric welding ground pad comprising, in combination, a cylindrical metallic tube for 1011- gitudinally receiving an insulated electric conductor, a metallic trough of generally U-shaped cross section integral with one end of said tube in longitudinal alignment and communicating therewith for longitudinally receiving a bare end portion of the conductor therefrom, means securing said bare conductor end portion in the trough, a permanent horseshoe magnet, and means securing said magnet beneath the free end portion of the trough, said trough having a series of longitudinally spaced openings in its bottom, the first-named means including a cylindrical tubular clamp of uniform diameter from end to end removably mounted longitudinally in the trough within the confines thereof and resting on the bare conductor end portion, said clamp having diametrically opposite openings therein at longitudinally spaced points aligned with the innermost of the first-named openings, and nutted bolts in the aligned openings passing through the bare conductor end portion for tightening the clamp thereon, the free end portion of the trough having the forwardmost of the first-named openings therein, said magnet having an opening therein at an intermediate point aligned with said forwardmost firstnamed opening, the second-named means including a nutted bolt engaged in the last-named aligned openings.

3. A portable electric welding ground pad as defined in claim 2, wherein said cylindrical tubular clamp has an outside diameter substantially corresponding to the inside width of the trough for sliding contact with the side Walls thereof.

References Cited in the file of this patent UNITED STATES PATENTS George July 16, Thomas Sept. 1, Lavarack Feb. 20, Bondeson Oct. 16, Wondriska Mar. 25, Rehder Aug. 23,

FOREIGN PATENTS Great Britain Oct. 27, Germany May 2, 

